[Heap Trace Standalone] do not allocate memory until init is called

components/heap/Kconfig

@@ -78,31 +78,28 @@ menu "Heap memory debugging"
             Enable this flag to use a hash map to increase performance in handling
             heap trace records.
 
-            Keeping this as "n" in your project will save RAM and heap memory but will lower
-            the performance of the heap trace in adding, retrieving and removing trace records.
-            Making this as "y" in your project, you will decrease free RAM and heap memory but,
-            the heap trace performances in adding retrieving and removing trace records will be
-            enhanced.
+            Heap trace standalone supports storing records as a list, or a list + hash map.
+
+            Using only a list takes less memory, but calls to 'free' will get slower as the
+            list grows. This is particiularly affected by HEAP_TRACE_ALL mode.
+
+            By using a list + hash map, calls to 'free' remain fast, at the cost of
+            additional memory to store the hash map.
 
     config HEAP_TRACE_HASH_MAP_IN_EXT_RAM
-        bool "Place hash map in the bss section of the external RAM"
-        depends on HEAP_TRACE_HASH_MAP && SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
+        bool "Place hash map in external RAM"
+        depends on HEAP_TRACE_HASH_MAP
         default n
         help
-            When enabled this configuration forces the hash map to be placed in the bss section
-            of the external RAM.
-
-            Note that this functionality can only be enabled when CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY
-            is enabled.
+            When enabled this configuration forces the hash map to be placed in external RAM.
 
     config HEAP_TRACE_HASH_MAP_SIZE
         int "The number of entries in the hash map"
         depends on HEAP_TRACE_HASH_MAP
-        default 10
+        default 512
         help
-            Defines the number of entries in the heap trace hashmap. The bigger this number is,
-            the bigger the hash map will be in the memory. In case the tracing mode is set to
-            HEAP_TRACE_ALL, the bigger the hashmap is, the better the performances are.
+            Defines the number of entries in the heap trace hashmap. Each entry takes 8 bytes.
+            The bigger this number is, the better the performance. Recommended range: 200 - 2000.
 
     config HEAP_ABORT_WHEN_ALLOCATION_FAILS
         bool "Abort if memory allocation fails"

components/heap/heap_trace_standalone.c

@@ -6,6 +6,7 @@
 #include <string.h>
 #include <sdkconfig.h>
 #include <inttypes.h>
+#include "esp_log.h"
 
 #define HEAP_TRACE_SRCFILE /* don't warn on inclusion here */
 #include "esp_heap_trace.h"
@@ -17,6 +18,8 @@
 #include "esp_memory_utils.h"
 #include "sys/queue.h"
 
+static const char* TAG = "heaptrace";
+
 #define STACK_DEPTH CONFIG_HEAP_TRACING_STACK_DEPTH
 
 #if CONFIG_HEAP_TRACING_STANDALONE
@@ -80,15 +83,10 @@ static size_t r_get_idx;
 
 #if CONFIG_HEAP_TRACE_HASH_MAP
 
-/* Define struct: linked list of records used in hash map */
-TAILQ_HEAD(heap_trace_hash_list_struct_t, heap_trace_record_t);
-typedef struct heap_trace_hash_list_struct_t heap_trace_hash_list_t;
-
-static
-#if CONFIG_HEAP_TRACE_HASH_MAP_IN_EXT_RAM
-EXT_RAM_BSS_ATTR
-#endif
-heap_trace_hash_list_t hash_map[(size_t)CONFIG_HEAP_TRACE_HASH_MAP_SIZE]; // Buffer used for hashmap entries
+// We use a hash_map to make locating a record by memory address very fast.
+//   Key: addr                  // the memory address returned by malloc, calloc, realloc
+//   Value: hash_map[hash(key)] // a list of records ptrs, which contains the relevant record.
+static heap_trace_record_list_t* hash_map; // array of lists
 static size_t total_hashmap_hits;
 static size_t total_hashmap_miss;
 
@@ -140,6 +138,19 @@ esp_err_t heap_trace_init_standalone(heap_trace_record_t *record_buffer, size_t
         return ESP_ERR_INVALID_ARG;
     }
 
+#if CONFIG_HEAP_TRACE_HASH_MAP
+    if (hash_map == NULL) {
+        uint32_t map_size = sizeof(heap_trace_record_list_t) * CONFIG_HEAP_TRACE_HASH_MAP_SIZE;
+#if CONFIG_HEAP_TRACE_HASH_MAP_IN_EXT_RAM
+        ESP_LOGI(TAG, "hashmap: allocating %" PRIu32 " bytes (PSRAM)\n", map_size);
+        hash_map = heap_caps_calloc(1, map_size, MALLOC_CAP_SPIRAM);
+#else
+        ESP_LOGI(TAG, "hashmap: allocating %" PRIu32 " bytes (Internal RAM)\n", map_size);
+        hash_map = heap_caps_calloc(1, map_size, MALLOC_CAP_INTERNAL);
+#endif // CONFIG_HEAP_TRACE_HASH_MAP_IN_EXT_RAM
+    }
+#endif // CONFIG_HEAP_TRACE_HASH_MAP
+
     records.buffer = record_buffer;
     records.capacity = num_records;
 

components/heap/test_apps/heap_tests/sdkconfig.ci.heap_trace_hashmap

@@ -1,6 +1,5 @@
 CONFIG_IDF_TARGET="esp32"
 CONFIG_SPIRAM=y
-CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY=y
 CONFIG_HEAP_TRACING_STANDALONE=y
 CONFIG_HEAP_TRACE_HASH_MAP=y
 CONFIG_HEAP_TRACE_HASH_MAP_IN_EXT_RAM=y